In the low pressure casting production of aluminum alloy wheels, shrinkage and pores are two common casting defects, resulting in up to 80% of the total waste. When high-temperature molten aluminum is filled, the entire mold is in an open atmosphere. If the air in the cavity cannot be removed smoothly, the air will gather at the distal rim of a casting and be finally wrapped in the molten aluminum, cannot escape during solidification, and therefore forms pores. The pores have the hazards of reducing the effective cross-sectional area of the product and reducing the safety performance of the rim. The root R angles at the junctions of spoke and the rim are obvious casting hot spots, the front spoke acts as a feeding channel, and sufficient heat is required during solidification to maintain the smoothness of the passage so as to powerfully feed the hot spots. The spoke should be maintained at a relatively high temperature, otherwise, the defects of shrinkage, porosity and the like easily occur at the R angles. At the same time, the low solidification rate causes coarse internal grains and loose structure of the casting to damage the mechanical properties of the casting, so that the casting cannot meet the strict requirements of customers.
In actual production, the above problems have seriously affected the forming quality of wheel castings and reduced the yield. Therefore, certain measures need to be taken for optimization and improvement to solve the problems of pores, shrinkage, coarse grain and the like of the castings, so as to achieve high-quality production of wheels.